JPS582278A - Manufacture of multi-layer ceramic substrate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention consists of 10. The present invention relates to a method for manufacturing a high-density circuit board on which elements such as LSI are mounted, and in particular to a method for manufacturing a multilayer ceramic substrate that provides means for forming -f on conductors for connection of the elements.

Ceramic substrates with compositions such as alumina ceramics have high mechanical strength (high thermal conductivity, and excellent electrical and chemical properties), so they are suitable for mounting and assembling L8I chips, which have recently become popular in large numbers. The present invention is directed to such ceramic substrates, and relates to a so-called three-dimensional circuit-forming substrate in which 80 or more unfired ceramic substrates (so-called green sheets) are laminated and fired. The object of the present invention is to provide a method that can efficiently form conductor terminals in each surface direction.

Such multilayer ceramic substrates usually have via holes for conductive connection between several layers between each layered circuit, and each side of the layered body has an external Si1 output for connecting functional elements (IC, LSI) to be mounted. It is common to provide a conductor terminal.

Conventionally, the via holes have been formed by press-fitting or filling metal conductor balls, and the interlayer connection circuits and external terminals have been formed by the following means.

That is, FIG. 1 is a sectional view showing how a pie hole is formed in a sheet body by a four-ball press-fitting method. In the figure, l
is the green sheet or sheet, 2 is the position of the pie hole array, and the conductor ball 5 of the array is pressed! lf4
This is an arrangement jig equipped with a through hole 6 that is press-fitted. 3 in the figure is a receiving mold for the pressing mold 4. As shown in FIG. For details on forming a pie hole using this press-fitting method, please refer to Japanese Patent Application No. 1983-130.
11 (filed on September 9, 1978).

The lower part of Figure 1 shows the single sheets 1 and 1 after the conductor balls are press-fitted.
' is shown, and between the front and back surfaces 7 and 8 of these sheets, a circuit having a conductor circuit formed by a mask pattern and a via hole are formed for the conductor 5.

A plurality of these single sheets are positioned and laminated, and this is phosphoricated at a predetermined temperature to form a multilayer Ceric substrate. - Can be formed by cutting at the position of the human index line. In other words, the ball conductor 5 located near the edge of the sheet is exposed and used as a terminal.

2 and l of the ball arrangement jig (Fig. 2).
Regardless of the high-precision alignment between the terminal (see O) and the sheet body 1, the conductor must be spherical, and if the substrate holding jig and grinding conditions are uneven during the side grinding work that produces the conductor mist, the lamination may occur. This is inconvenient because it causes variations in the terminal surfaces between the upper and lower boards.

In the case of uneven grinding, there is a situation where the conductor is not exposed on the lower substrate 1' side (the diagram is exaggerated to clarify the problem).

An object of the present invention is to eliminate the above-mentioned disadvantages. In order to achieve the object, the present invention includes a step of press-fitting a cylindrical conductor member into an unphosphorized ceramic substrate so that the axis of the cylindrical conductor member and the surface of the unphosphorized ceramic substrate are approximately parallel; A method of manufacturing a multilayer ceramic substrate is characterized by comprising a step of laminating and phosphoricating the fired substrate, and a step of exposing the columnar conductor member by grinding the side surface of the fired substrate.

An embodiment of the present invention will be explained below with reference to FIGS. 2 and 3, which illustrate one embodiment of the present invention. FIG. 2 is a perspective view sequentially illustrating the work steps of manufacturing the board, and FIG. 3 is a perspective view illustrating a grinding means for exposing terminals.

In Fig. 2, the figure shows the state before press-fitting, in which the ball conductor 5 is positioned within the frame using the arrangement jig 2 and the jig fixing frame 10 placed on the green sea) 1. The state of the sheet after the conductor balls 5 are press-fitted into the sheet 1 is shown. The size of the ball is, for example, a ball with a diameter of 0.34 w1 degrees, taking into account high-density wiring patterns and the like.

Figure 0 is a continuation of the process shown in Figure ■, where a cylindrical conductor as a terminal conductor, which is the essential part of the present invention, for example, a diameter of 0.34■, and a conductor with a length of about 1 inch are similarly applied to sheet 1 four times. This figure shows the state before the cylindrical conductors 12 are press-fitted after being aligned and positioned by the guides 11. When the arrangement of the conductors 12 on the four sides of the sheet is completed, the conductors are enlarged using a hydraulic press (not shown) in Figure 0.

The arrangement of the conductors 5 and 12 is merely an example, and as shown in the figure, a large number of pie hole forming portions are arranged in a high-density arrangement in the center of the sheet, and on the other hand, a large number of externally exposed conductor terminals are arranged on the outer side of the sheet. provided.

FIG. 3 is a perspective view of a multilayer laminate 14 in which a large number of sheets 13 with the circuit pattern 4 which have undergone the 210th step are piled up and pressed to form a multilayer, and phosphoricated in a 900C furnace.

Each rain 15~Ml 9 (there are 5Th) of the laminate 14 is
Surface grinding or surface polishing is performed to form a terminal using a cylindrical terminal conductor. For example, in the illustration, the conductor 2 is placed on the side surface 15 of the board.
Indicates the situation in which the exposure was made. Of course, the other side surfaces 16 to 19 are also internally polished. In this way, all surfaces of the substrate body 14, including the bottom surface, become surfaces on which functional elements are mounted and exposed to the outside, and pad-shaped conductor terminals are formed within these surfaces. The arrangement example of the conductor terminals (the surface 15 shown in the drawing has a DIPfi♀ configuration) is not limited to the - example. It is also possible, for example, to form conductor terminals for array elements of flat-pack construction.

According to the method for manufacturing a multilayer top-floated board according to the present invention having the above-mentioned trajectory, the difficulty of grinding the board side surface due to the shape defect of the spherical conductor terminal is eliminated, and the workability during grinding is also improved. To easily manufacture and provide an inexpensive ceramic substrate.

From this perspective, the industrial effects of the present invention are significant.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing a conventional method for manufacturing a ceramic ceramic board, and FIGS. 2 and 3 are perspective views for explaining the method for manufacturing a multilayer ceramic board according to the present invention, and examples of carved substrates. FIG. In the figure, 1 is the phosphoric acid front sheet, 3 and 4 are both the ball conductor 5
9 is a side surface of the substrate sheet, 12 is a cylindrical conductor, 13 is a completed sheet into which conductors 5 and 12 are press-fitted, 14 is a multilayer ceramic substrate body, 15.16.17.1
Both 8 and 19 are the side surfaces of the phosphoric acid substrate. 1st flash 3rd (2) ♀Z fXl (A)

Claims (1)

[Claims] In a method for manufacturing a multilayer ceramic substrate having a plurality of conductor terminals and a plurality of wire holes for interlayer connection, a cylindrical conductor member is placed on an unfired ceramic substrate so that the axis of the cylindrical conductor member and the surface of the unfired ceramic substrate are parallel to each other. A multilayer ceramic board characterized by comprising a step of press-fitting the unfired ceramic substrates so that the substrates are formed, a step of laminating and firing the unfired ceramic substrates, and a step of exposing the cylindrical conductive member by one-sided polishing of the fired substrate. manufacturing method.